Color Management Through PowerRIPX
After quite a bit of time and effort, here is what I know about color management on the 5th floor Epson printers. The results make it clear that color management is not part of a reasonable color managed workflow here. While good practices are better than bad practices, good practices will not give you the accuracy that the software and equipment is capable of. Here are three things that could be done to improve the situation.

1. Get custom profiles made for the paper being used. It would cost $40 per printer/paper combination, or $160 once a decision is made on what paper will be available in each printer. Other profiles can be made as needed. One impediment to profiling through the rip is the need to turn all default corrections off, and it isn't clear to me how to do this without bypassing the rip altogether.

2. Once the custom profiles are made and installed, the PowerRIP X software should be set up to take advantage of them. In addition to setting up the default profile for each printer, there are other default settings that should be changed to take advantage of them. Currently the defaults are for CMYK simulation of some unknown process, so that unless you turn color management OFF you will NEVER see the best possible output from a rgb file.

3. Finally, to be able to preview printed outcomes users need to have the profiles for these printer/paper combinations on their systems. Each computer that accesses the printers should have the profiles on its system so that users can choose that profile from Photoshop's print preview. At that point, users should let Photoshop manage their color and send the file to the printer with "No Color Adjustment" checked in the print dialog.

Better instructions later when they'll do more good. Meanwhile, Real World Color Management remains a great resource for understanding the process.